Re: Class device namespaces

[David Dillow <dave@thedillows.org>]

On Wed, 2009-04-29 at 23:53 +0200, Kay Sievers wrote:
> On Wed, Apr 29, 2009 at 23:28, Michael Brown <mebrown@michaels-house.net> wrote:
> > I cant say that I've ever seen any problems due to udev
> > cancelling a firmware request.  In fact, if I manually trigger a
> > request using "echo" from the cmdline, I dont see udev take any action
> > with the dell_rbu device. eg (Fedora 10, udev-127-5.fc10):
> 
> If you run:
>   udevmonitor --udev --env
> at the same time, what does it say?
> 
> > I dont see any of the behaviour that you have talked about. If I let
> > it sit there for hours, it will stay at that state. It only closes up
> > the request_firmware() request when I echo 0 > loading.
> 
> Udev will run in the moment this sysfs device is created, and it
> should trigger the removal of the device, if it does not find the
> requested firmware file.

drivers/firmware/dell_rbu.c does this:
req_firm_rc = request_firmware_nowait(THIS_MODULE,
                                FW_ACTION_NOHOTPLUG, "dell_rbu",
                                &rbu_device->dev, &context,
                                callbackfn_rbu);

I've not gone looking to verify, but FW_ACTION_NOHOTPLUG implies to me
that udev never sees a uevent for it.